Estimating branch circuit load

I'm converting a living room into an office space in my house. I'll be doing my own rewiring and am in the process of estimating the load on my electric service. I've accounted for all the known loads (computers & lighting) but I'm not sure how to estimate the demand that might be placed on the general use outlet circuits. Here are the details I have:

There will be 2 15A circuits, each supplying 6 outlets (probably overkill but I'll have room on the subpanel I'm putting in).

I've already accounted for all computers, monitors and peripherals with their own separate circuit. All task and area lighting is also on its own circuit.

Typically, I can only see using the general outlets for small stuff like pencil sharpeners, mug warmers, etc. and occasionally the vacuum.

Any suggestions on how to guesstimate potential load on a general use outlet circuit when you're not sure what will be on it?

My first suggestion is to use 20 amp circuits. It makes no sense whatsoever if you are starting from scratch to install 15 amp circuits when 20 amp circuits give you one third more power at minimal additional cost.

Don't worry about the small things, especially if they are only occasionally used. This would include the pencil sharpener you mention, a shredder, a fax machine, etc.

It's the large items you need to be concerned about. This includes space heaters, the vacuum cleaner, etc.

It sounds like you have the right idea, just make them 20 amp circuits.